The hydroxyapatites were popularly been used as the ocular implant due to low incidence of post-operative exposure, infections, and excellent motility. For this purpose, it has been known that the drilling and peg implantations are performed after ingrowth of fibrovascularization tissue into the hydroxyapatites, so that ball and socket movement were occur. The authors reviewed 140 patients(140 eyes) who received enucleation or evisceration with the implantation of hydroxypapatite from Dec. 1991 to Jun. 1995. We performed that drilling after confirmation of the fiborvascularized hydroxyapatite by Technetium-99m-MDP bone scan, and investigated the method and complications. Among the 140 eyes(140 Patients), 39 eyes(28%) were found to have complications: 17 cases of peg extraction(44%), 10 cases of peg protrusion(26%), 4 cases of over-growth of granulation tissue(11%), 3 cases of poor motility(7%), 3 cases of hydroxyapatite exposure(7%) and 2 cases of malposition of peg(5%). Redrilling was performed in 20 eyes(51%) and exchanged by the screw peg due to re-extraction of peg in 4 eyes(20%). In a conclusion, overall the frequency of complications after drilling was about 28% and the most frequent complication was peg extraction.
Durapatite* ; Humans ; Hydroxyapatites ; Incidence

The change of conditions of hydroxyapatite synthesis can affect not oniy the material properties, but also the body reaction to the hydroxyapatite implants. To find out conditions for preparing more biocompatible hydroxyapatite implants as bone graft substitute. we evaluated the biologic response to the dense synthetic hydroxyapatite implants, made with various synthetic conditions, placed in corticocancellous defects of rabbits' long bone. The hydroxyapatites were synthesized with coprecipitation technique using Ca(NO3) 4H2O and (NH4)2HPO4, made with various Ca/P ratio and aging temperatures. Four kinds of hydroxyapatites were selected to use as implants(HA I: Ca/P ratio 1.5, aging temperature 90degrees C; HA V :1.5 , 30degrees C; HA VI: 1.83, 30degrees C; and HA lX: 1.67, 30degrees C). These hydroxyapatites were pressed and sintered at l300degrees C to fabricate dense plates. Biomechanical test and rnorphological examination were performed using Instron, light microscope and electron microscope. The characteristics of hydroxyapatite powder and sintered body were more significantly affected by siarting Ca/P ratios. The bonding strength of HA IX(1.67, 30degrees C) with bone was grcatest at 4 or 8 weeks after implantation with statistically significant difference(p<0.05). Bonding behavior betweeb HA IX and bone was most excellent in terms of new bone formation and new bone ingrowth into resorbed surface of hydroxyapatite plate.
Aging ; Durapatite* ; Hydroxyapatites ; Osteogenesis ; Transplants

STUDY DESIGN: Retrospective study. PURPOSE: To compare the union rate of posterolateral lumbar fusion (PLF) using demineralized bone matrix (DBM) versus hydroxyapatite (HA) as bone graft extender. OVERVIEW OF LITERATURE: To our knowledge, there has been no clinical trial to compare the outcomes of DBM versus HA as a graft material for PLF. METHODS: We analyzed prospectively collected data from consecutive 79 patients who underwent instrumented PLF. Patients who received DBM were assigned to group B (n=38), and patients who received HA were assigned into group C (n=41). The primary study outcome was fusion rate assessed with radiographs. The secondary outcomes included pain intensity using a visual analogue scale, functional outcome using Oswestry disability index score, laboratory tests of inflammatory profiles and infection rate. RESULTS: One year postoperatively, bone fusion was achieved in 73% in group B and 58% in group C without significant difference between the groups (p=0.15). There were no differences between the groups with respect to secondary outcomes. CONCLUSIONS: DBM would provide noninferior outcomes compared to the HA as a fusion material for PLF, and could be a notable alternative.
Bone Matrix* ; Durapatite* ; Humans ; Hydroxyapatites ; Prospective Studies ; Retrospective Studies ; Transplants

PURPOSE: The purpose of this study was to histomorphometrically evaluate the osteoconductivity of a new biphasic calcium phosphate ceramics with fully interconnected microporous structure. MATERIAL AND METHODS: Osseous defects created in the rabbit calvaria were filled with four different bone graft substitutes. Experimental sites were filled with a new fully interconnected microporous biphasic calcium phosphate with(BCP-2) or without(BCP-1) internal macropore of 400micrometer in diameter. MBCP(Biomatlante, France) and Bio-Oss(Geistlich Pharma, Switzerland) were used as controls in this study. Histomorphometric evaluation was performed at 4 and 8 weeks after surgery. RESULT: In histologic evaluation, new bone formation and direct bony contact with the graft particles were observed in all four groups. At 4 weeks, BCP-1(15.5%) and BCP-2(15.5%) groups showed greater amount of newly formed mineralized bone area(NB%) compared to BO(11.4%) and MBCP(10.3%) groups. The amounts of NB% at 8 weeks were greater than those of 4 weeks in all four groups, but there was no statistically significant differences in NB% between the groups. CONCLUSION: These results indicate that new bone substitutes, BCP with interconnected microporous structure and with or without internal macroporous structures, have the osteoconductivity comparable to those of commercially available bone substitutes, MBCP and Bio-Oss.
Bone Substitutes ; Calcium ; Ceramics ; Hydroxyapatites ; Minerals ; Osteogenesis ; Skull ; Transplants

PURPOSE: The purpose of this study was to determine the biological effects of cyanoacrylate-combined calcium phosphate (CCP), in particular its potential to act as a physical barrier - functioning like a membrane - in rabbit calvarial defects. METHODS: In each animal, four circular calvarial defects with a diameter of 8 mm were prepared and then filled with either nothing (control group) or one of three different experimental materials. In the experimental conditions, they were filled with CCP alone (CCP group), filled with biphasic calcium phosphate (BCP) and then covered with an absorbable collagen sponge (ACS; BCP/ACS group), or filled with BCP and then covered by CCP (BCP/CCP group). RESULTS: After 4 and 8 weeks of healing, new bone formation appeared to be lower in the CCP group than in the control group, but the difference was not statistically significant. In both the CCP and BCP/CCP groups, inflammatory cells could be seen after 4 and 8 weeks of healing. CONCLUSIONS: Within the limits of this study, CCP exhibited limited osteoconductivity in rabbit calvarial defects and was histologically associated with the presence of inflammatory cells. However, CCP demonstrated its ability to stabilize graft particles and its potential as an effective defect filler in bone augmentation, if the biocompatibility and osteoconductivity of CCP were improved.
Animals ; Bone Regeneration ; Calcium ; Calcium Phosphates ; Collagen ; Cyanoacrylates ; Hydroxyapatites ; Membranes ; Osteogenesis ; Porifera ; Rabbits ; Transplants

PURPOSE: The preferred material for bone augmentation beyond the envelope of skeletal bone is the bone block graft, due to its dimensional stability. We evaluated the necessity of rigid fixation for the bone block graft, and compared the bone regeneration and volume maintenance associated with grafting using a synthetic hydroxyapatite block (HAB) and an autogenous bone block (ABB) without rigid fixation on rabbit calvaria over two different periods. METHODS: Cylinder-shaped synthetic HAB and ABB were positioned without fixation on the rabbit calvarium (n=16). The animals were sacrificed at 4 or 8 weeks postoperatively, and the grafted materials were analyzed at each healing period using microcomputed tomography and histologic evaluation. RESULTS: Integration of the graft and the recipient bed was observed in all specimens, although minor dislocation of the graft materials from the original position was evident in some specimens (six ABB and ten HAB samples). A tendency toward progressive bone resorption was observed in the grafted ABB but not in the grafted HAB, which maintained an intact appearance. In the HAB group, the area of new bone increased between 4 and 8 weeks postoperatively, but the difference was not statistically significant. CONCLUSIONS: The nonfixed HAB was successfully integrated into the recipient bed after both healing periods in the rabbit calvaria. In spite of limited bone formation activity in comparison to ABB, HAB may be a favorable substitute osteoconductive bone material.
Animal Experimentation ; Animals ; Bone Regeneration ; Bone Resorption ; Dislocations ; Durapatite* ; Hydroxyapatites ; Osteogenesis ; Skull* ; Transplants* ; X-Ray Microtomography

PURPOSE: In this study, the effect of micro-macroporous biphasic calcium phosphate(MBCP) incorporated with inorganic polyphosphate for bone regeneration in the calvaria of rabbit was evaluated. MATERIALS AND METHODS: The procedure of guided bone regeneration was performed with titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. Four animal groups were compared : 1) TR-ePTFE membrane for negative control group, 2) TR-ePTFE membrane filled with MBCP for positive control group, 3) TR-ePTFE membrane filled with MBCP soaked in 4% inorganic polyphosphate for experimental group I, and 4) TR-ePTFE membrane filled with MBCP soaked in 8% inorganic polyphosphate for experimental group II. RESULTS: 1. Negative control group showed the highest new bone formation at 16 weeks. 2. Positive control group showed the smallest new bone formation compared to other groups. 3. 8% inorganic polyphosphate induced more volume of bone formation, otherwise experimental group II did not show significant difference compared to negative control group. CONCLUSION: These results suggest that inorganic polyphosphate has a promoting effect on bone regeneration, possibly by enhancing osteoconductivity of the carrier and by increasing osteoinductivity of the defected alveolar bone tissue.
Animals ; Bone and Bones ; Bone Regeneration ; Calcium ; Hydroxyapatites ; Membranes ; Osteogenesis ; Skull ; Titanium

PURPOSE: The aim of this study was to evaluated biphasic calcium phosphate applied in surgically created 1-wall periodontal intrabony defects in dogs by histometrical analysis. MATERIAL AND METHOD: Critical sized(4 mm x 4 mm), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four canines. The control group was treated with debridement alone, and experimental group was treated with debridement and biphasic calcium phosphate application. The healing processes were histologically and histometrically observed after 8 weeks. RESULTS: In biphasic calcium phosphate group, more new bone and cementum formation, less epithelium and connective tissue attachment were observed compared to other groups. But there was no statistical significance. CONCLUSION: Though the statistically significant difference could not be found, it seemed that there was more new bone and cementum formation with applying biphasic calcium phosphate in 1 wall intrabony defects in dogs by preventing junctional epithelium migration.
Animals ; Bicuspid ; Calcium ; Connective Tissue ; Debridement ; Dental Cementum ; Dogs ; Epithelial Attachment ; Epithelium ; Hydroxyapatites ; Jaw

PURPOSE: The carrier for the delivery of bone morphogenetic proteins(BMPs) should also serve as a scaffold for new bone growth. In addition, predictable bone formation in terms of the volume and shape should be guaranteed. This study evaluated the ectopic bone formation of recombinant human BMP-2(rhBMP-2) using a micro macroporous biphasic calcium phosphate (MBCP: mixture of betaTCP and HA) block as a carrier in a rat subcutaneous assay model. MATERIALS AND METHODS: Subcutaneous pockets were created on the back of 40 male Sprague-Dawley rats. In the pockets, rhBMP-2/MBCP and MBCP alone were implanted. The blocks were evaluated by histological and histometric parameters after a healing interval of 2 weeks (each 10 rats; MBCP and rhBMP-2/MBCP) or 8 weeks (each 10 rats; MBCP and rhBMP-2/MBCP). RESULTS: The shape and volume of the block was maintained stable over the healing period. No histological bone forming activity was observed in the MBCP alone sites after 2 weeks and there was minimal new bone formation at 8 weeks. In the rhBMP-2/MBCP sites, new bone formation was evident in the macropores of the block. The new bone area at 8 weeks was greater than at 2 weeks. There was a further increase in the quantity of new bone with the more advanced stage of remodeling. CONCLUSIONS: A MBCP block could serve as a carrier system for predictable bone tissue engineering using rhBMPs.
Animals ; Bone and Bones ; Bone Development ; Calcium ; Humans ; Hydroxyapatites ; Male ; Osteogenesis ; Rats ; Rats, Sprague-Dawley ; Subcutaneous Tissue

PURPOSE: The carrier used as delivery agent for bone morphogenetic proteins(BMPs) should also act as a scaffold for new bone formation. Moreover, bone formation should be predictable in terms of the volume and shape. This study examined the osteogenic effect of macroporous biphasic calcium phosphate (MBCP) block combined with ePTFE membrane as a carrier for recombinant human bone morphogenetic proteins (rhBMP-2). In addition, the additive effect of ePTFE membrane on bone formation was evaluated. MATERIALS AND METHODS: Eight-millimeter critical sized calvarial defects were created surgically in 28 male Sprague-Dawley rats. The animals were divided into 2 groups containing 14 animals each. The defects were treated with either rhBMP-2/MBCP block (rhBMP-2/MBCP group) or rhBMP-2/MBCP block/ePTFE membrane (rhBMP-2/MBCP/ePTFE group). A disc-shaped MBCP block (3 mm height and 8 mm diameter) was used as the carrier for the rhBMP-2 and ePTFE membrane was used to cover the rhBMP-2/MBCP block. The histologic and histometric parameters were used to evaluate the defects after 2- or 8-week healing period (7 animals/group/healing interval). RESULTS: The level of bone formation in the defects of both groups was significantly higher at 8 weeks than that at 2 weeks (P < 0.05). The ePTFE membrane has no additional effect compared with the rhBMP-2/MBCP block only. However, at 8 weeks, rhBMP-2/MBCP/ePTFE group showed more even bone formation on the top of the MBCP block than the rhBMP-2/MBCP group. CONCLUSION: These results suggest that the ePTFE membrane has no additive effect on bone formation when a MBCP block is used as a carrier for rhBMP-2.
Animals ; Bone Morphogenetic Proteins ; Calcium ; Durapatite ; Humans ; Hydroxyapatites ; Male ; Membranes ; Osteogenesis ; Rats ; Rats, Sprague-Dawley